Sennabean, Drummond Sesbania

Sesbania drummondii

Fabaceae (Legume family)


Sennabean is a woody-based perennial shrub of the legume family that grows to about 2 to 10 feet tall. Twenty to 40 leaflets are arranged opposite along a main axis with leaves up to 8 inches long. Yellow flowers are borne in spikes in late summer. The seedpod often remains closed and on the plant over the winter. It has a very characteristic four-winged structure with constrictions and cross partitions between the seeds.


Sennabean grows in East and South Texas along the coast, extending inland along waterways. It is found in wet areas, usually in tight soil, and often grows in shallow water.

Toxic Agent

Sennabean plants contain sesbaimide, which is concentrated in the seed. The green and flowering plants are unpalatable; only the mature, dry legumes and seed are consumed. Animals raised in pastures with the plant learn to avoid it and are seldom poisoned. However, naïve cattle, goats or sheep placed on pastures containing dried plants in late fall and winter are often poisoned. Observations of field cases indicate that seeds are much more toxic when they first mature than 2 or 3 months later.

Signs of Livestock Ingestion

Signs of poisoning occur within 1 or 2 days after ingestion and may include: Depression; Diarrhea; Weakness; Rapid heart rate; Labored breathing; Death.

Clinical signs progress rapidly; sick animals often die within 24 hours. Diagnosis is confirmed when seeds and/or seed fragments are found in the rumen contents.

Management Strategies

In general, good range management practices can reduce poisoning instances. Avoid placing hungry, naive ruminants in pastures containing mature Sesbania seedpods. Fill newly introduced animals with hay before releasing them; do not place them in heavily infested pastures without supplemental feed.